As a user I can search for comics by tag

[thomasMinshull]

Is your feature request related to a problem? Please describe.
XKCD comics are not easily searchable. By associating comics with tags and making those comics searchable by tags, it will be easier for users to find comics that are related to a specific topic.

Describe the solution you'd like
A use should be able to select a pre-defined tag and see all the comics associated with that tag